I work in a non customer / public facing role in an office. Today as it was hot I wore an nice knee length A-line skirt and a T-shirt. All very respectable. Think White Stuff style. With ballet flats.
One of the more senior managers pulled me up and said that bare legs and a casual skirt weren’t appropriate. She was wearing linen culottes and flip flops.
In my last job I would wear a maxi dress and sandals in the heat but there was no formal dress code. I looked at the dress code for this workplace and it’s smart-casual. Knee length skirts and smart tops are in the acceptable column. Flip flops are not.
Normally I would wear a smartish work dress with tights but it’s just too sticky and the office has poor ventilation.